Genes/chromosomes

Human characteristic can be inherited or an environmental factor

-domainant or recessive

Alleles:different versions of the same gene

Humans have 23 pairs

Females: **

Males: xy

Genetic variation is caused by:
-mutation (random changes in genes or chromosomes)
-rearrangement of genes during the formations of garmetes
-fertilisation (results in zygote from the fathers and mother)

17 of 21

Alcohol

Alcohol increases reaction times and increases accidents

Short term effects: blurred vision/slurred speech/increased blood flow to skin